Study Of Individual Tree Growth Model For Chinese Fir Plantation

To explore a Chinese fir plantation individual tree growth model of a simple form and easy production and application, Chinese fir plantation in forestry cutting and breeding field in erdu of Shaowu City is chosen as the object of the study in this paper. Chinese fir plantation individual tree growth model is studied on the basis of the data of individual tree with fixed positioning on the monumented sample and conventional sample-plot with the application of a variety of modeling techniques.Two individual tree competition indexes are selected with related to distance and unrelated to distance in this paper and the individual tree growth model is established by using the regression analysis method, the potential growth method and artificial neural network method. The results show that in the individual tree growth model related to distance with a simple competition index as the competition index, individual tree growth model is simulated by exponential function, power function, the growth potential method and artificial neural network method, and fitting accuracy is respectively 87.8%, 88.66%, 86.21%, 91.75%. In the individual tree growth model unrelated to distance with the crown area as competition index, the above three methods are also used for fitting, namely linear regression model, power function, the potential growth and artificial neural network method, and its fitting accuracy is respectively 88.4%, 88.67%, 87.34%, 96.77%. The results show that in the individual tree growth model unrelated to the distance, its ability to fit and forecast accuracy will not be reduced because of the lack of the relevant spatial information and at the same time its competition index also has the advantages of simple calculation method and easy application. Therefore, whether the potential of application or the prospects of development, in the long run, the individual tree growth model unrelated to the distance will be an important research direction in future; At the same time, compared with the traditional individual tree growth model in modeling methods, artificial neural network approach is superior to others and has a higher accuracy.The individual tree growth model for Chinese fir plantation which is constructed in this paper reflects objectively the growth dynamics of Chinese fir plantation the location of study, simulates the growth process of Chinese fir plantation more preferably, and provides detailed information for intensive management and production decision-making on tree growth in the region,which has theoretical and practical value in a certain degree.